1. Field of the Invention
The present invention relates generally to a vibration damper for damping the vibration of a suspended cable and more particularly to a vibration damper in which a spring is effective to damp vibrations of the suspended cable.
2. Description of the Prior Art
It is well known that suspended cables are subjected to air currents moving across them which tend to move and vibrate the cables. If the period of vibration caused by air currents moving across a cable coincides with its natural period of oscillation or a harmonic thereof, the cable is then subjected to a sustained mechanical vibration which causes a continuously repeated bending of the cable at its support locations. Such bending causes fatigue of the metal of the cable resulting in failure of the cable at the support locations. Further, such cable movement causes wear on its associated and supporting hardware.
Thus, the importance of preventing vibration as a means of eliminating excessive wear and fatigue of cables is well recognized. Damping by introduction of frictional forces to reduce the vibration amplitude has long been applied and many damper designs have been used.